Hi Katie!
I admit that I'm jealous.... five trips to Disney sounds great. I love Disney. I don't mind staying on site, but I prefer to stay offsite.
This trip we are renting a large house and we couldn't be more excited. We don't really use the perks of staying onsite regularly. We don't bother with EMH since we use TourGuideMike's advice. We might miss charging privileges, but we plan on getting Disney gift cards, and just recharging as needed to help control our spending. We plan to eat offsite quite a bit, since we are not really "fancy food" eaters, and we feel the quality of WDW food is becoming more average. We also prefer to drive to the parks rather than taking the bus. The buses can be very crowded, and you sometimes wait a good while at the end of the day to catch a bus... then sometimes have to stand on the bus all the way back to your resort.
Now at the villa we're renting.... we have a private heated pool and jacuzzi right out our back door that we don't have to share with rowdy teens. We get to park our car at our door. We have high end pillow top mattresses and linens. The house also has its own games room with pool table and air hockey table, and a fabulous theater system in the living room. Honestly, the house isn't any farther away from WDW parks than OKW.
We love OKW, and it is the only resort that we would consider returning to on property. We love the fact that it is so spacious and peaceful and quiet.. not over the top Disney. But lots of people don't like OKW, because they think it doesn't feel as "Disney'd" as the other resorts. In the end, it is so much more money to stay onsite at OKW then to rent a luxury pool villa - especially when we don't really use the onsite perks. So it make more sense to us to stay offsite.
You might want to give it a try for one of your upcoming trips ( or split your stay if you'll be staying 10-14 days. Since you're going so often this year, you'll be able to compare the onsite vrs. offsite experience pretty readily.
Lisa